Dear Chaitra,
A suitable question at this juncture.
Many people have doubts about fall protection requirements. Most of them seek shelter under regulations.
Of course regulations are helpful and few areas cannot be managed without the stringent statutes.
My answers are with a broader perspective and in an industrial context.
A person can fall on the same level or from any height. We consider fall from height so seriously though falling on same level cannot be taken lightly.
Here fall protection needed at height is considered.
We can protect a person from falling to a lower level by 1) fall protection system and 2) fall arrest system.
Examples of fall protection system are parapet on a terrace, guard rails, barricading or covering of opening at height and so on.
Examples of fall arrest system are full body harness with lanyard, positioning devices, nets and so on.
Here the question is at what height we need fall protection ?
Answer is any height from where a person can fall and sustain injury.
This answer is not satisfactory.
Here we have to analyze. A fall from what height can cause severe injury or fatality.
A fall from 0.3 meters to 1.2 meters seldom result in a fatality. However falls from a height of 1.8 meters mostly results in severe head injuries and fatality.
With the above; one can easily conclude that over 1.8 meters we need fall protection and it is as simple as that.
Now the regulations vary from country to country. In India it is over 3 meters.
In USA, as per OSHA, for general industry it is over 1.2 meters and in construction 1.8 meters.
Coming back to your posting, please note that the use of safety belt is not advised and better avoid it. We have to advise use of full body harness only and there are solid reasons behind it.
At what height you can work without safety harness? Answer is; at any height where other means of fall protection system is provided !
For using a safety harness with a 1.8 meter lanyard the minimum free fall distance should be + 4 meters. However with a shock absorbing lanyard the minimum free fall distance should be 6 meters without which use of safety harness is of no use.
Hope you make it.
Regards,
Kesava Pillai